JP4254474B2 - Magnetoresistive thin-film magnetic head and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multi-track magnetoresistive thin film magnetic head and a method of manufacturing the same.

  In recent years, in the field of magnetic recording, there is an increasing need to record and reproduce a large amount of signals such as high-quality audio data and high-quality video data, and it is desired to increase the capacity and transfer rate of storage media. ing.

  Conventionally, as a magnetic recording / reproducing apparatus for recording and reproducing data using a magnetic tape, a magnetic tape is helically wound around a rotating drum having a magnetic head on its peripheral surface to record and reproduce a signal. A helical scan system that performs the above is known. In this helical scan system, the magnetic head slides obliquely at a high speed on the traveling magnetic tape to record and reproduce signals, so that the relative sliding speed between the magnetic tape and the magnetic head is high, thereby recording. Improvements in density and data transfer rate have been realized.

  Therefore, as a method of realizing a higher transfer rate, a plurality of magnetic heads are arranged on the circumferential surface of the rotating drum in the track width direction, so that recording and reproduction on a plurality of tracks can be performed simultaneously. A multi-track head is known (Patent Document 1 below).

  On the other hand, a so-called thin film magnetic head, in which the constituent elements constituting the head element are laminated by a thin film forming process, has attracted attention as a magnetic head corresponding to an increase in recording density. A thin film magnetic head has a feature that a thin film layer such as a magnetic film and a nonmagnetic insulating film is formed by a vacuum thin film forming technique, and therefore it is easy to make a fine dimension such as narrowing a track or narrowing a gap. .

  For example, in a hard disk drive or the like, a composite type thin film magnetic head that combines an inductive type thin film magnetic head using electromagnetic induction as a recording-only head and a magnetoresistive type thin film magnetic head using the magnetoresistive effect as a read-only head. A head has been put into practical use (see Patent Documents 2 and 3 below).

  Above all, the magnetoresistive thin film magnetic head uses the magnetoresistive effect phenomenon in which the electric resistance value changes depending on the angle between the direction of magnetization and the direction of the current flowing inside, and the reproduction output depends on the medium speed. In addition, a high reproduction output can be obtained even at a low medium speed.

  In a magnetoresistive thin film magnetic head, when a magnetoresistive element receives a leakage magnetic flux from a magnetic recording medium, the direction of magnetization of the magnetoresistive element is reversed by the magnetic flux, and the current flowing inside the magnetoresistive element It has an angle corresponding to the amount of magnetic flux with respect to the direction. Therefore, the electric resistance value of the magnetoresistive effect element changes, and a voltage change corresponding to the change amount appears on the electrodes at both ends of the magnetoresistive effect element through which a current flows. Therefore, the magnetic recording signal can be read using this voltage change as a voltage signal.

  A magnetoresistive thin film magnetic head is formed by forming a magnetoresistive effect element, an electrode film, an insulating layer, etc. on a substrate by thin film technology, and etching them into a predetermined shape by photolithography technology. In order to define the gap length and prevent the unnecessary magnetic flux from entering the magnetoresistive effect element, a shield structure in which a lower magnetic pole and an upper magnetic pole serving as a shield material are arranged vertically is employed.

  By the way, in the digital tape recorder, the amount of signals to be recorded is dramatically increased as compared with a normal analog tape recorder. Therefore, in the field of the magnetic head, a multi-track structure is adopted in order to cope with an increase in digital recording density. There is a growing demand for magnetic heads.

  However, as described in Patent Document 1 below, in a conventional magnetic head adapted for multi-tracking by arranging a plurality of reproducing head chips on the peripheral surface of a rotating drum, each head chip It is extremely difficult to adjust the gap spacing between the tracks and align the track height with high accuracy, and the mounting work of the head chip to the rotating drum is difficult and complicated, and there are significant problems in terms of yield and manufacturing cost. ing.

  In addition, although the composite thin film magnetic heads described in Patent Documents 2 and 3 have dedicated magnetic heads for recording and reproduction, it is not possible to simultaneously perform reproduction operations on a plurality of tracks. This is a possible configuration.

  Therefore, in order to provide a multi-track magnetoresistive thin film magnetic head capable of faithfully reproducing recorded signals and excellent in productivity, the present applicant has first proposed a magnetoresistive as viewed from the sliding surface with the magnetic recording medium. A magnetoresistive effect type thin film magnetic head having a structure in which two or more magnetoresistive effect elements are stacked by shifting each other in the track width direction through a shield material made of a magnetic material with the formation width of the effect element as a track width is proposed. (Japanese Patent Application No. 2003-74264).

  In the magnetoresistive thin film magnetic head according to the invention of the above-mentioned application, since the magnetoresistive effect elements are stacked with two or more layers being shifted from each other in the track width direction via a shield material made of a magnetic material, a plurality of tracks A high-performance thin-film magnetic head for reproduction that can be used for multi-tracking, can prevent unnecessary magnetic flux from entering each magnetoresistive element with a shield material between layers. It is possible to manufacture with a high yield with fewer processes.

  In addition, there are the following as prior art documents related to the invention of this application.

JP 2002-298570 A JP-A-10-149520 JP-A-10-198930 Japanese Patent Publication No. 8-33978

  As described above, in a magnetoresistive thin film magnetic head having a structure in which magnetoresistive elements are laminated in multiple layers by shifting them in the track width direction via a shield material made of a magnetic material, the magnetoresistive effect of each layer is The change in the electric resistance value of the element, that is, how efficiently the wiring pattern for taking out the reproduction output is led out greatly affects the chip size of the magnetic head.

  For example, FIG. 20 is a plan view of the head chip 1 schematically showing the state of the uppermost layer of a multi-layered magnetoresistive thin film magnetic head for eight tracks on which eight magnetoresistive elements are mounted. Since each magnetoresistive effect element is provided with a pair of wiring patterns for detecting the reproduction output, two terminals per element, that is, a total of 16 external connection terminals 2 are formed on the top layer of the head chip. Become.

  Therefore, as shown in FIG. 20, after the interlayer wiring patterns 4 connected to the reproduction leads 3 formed in the process of forming each element and led out to the top layer of the chip are arranged and formed for each element, A method of forming in-plane wiring patterns 5 for connecting these interlayer wiring patterns 4 to the external connection terminals 2 at the same time in the uppermost layer of the chip can be considered.

  However, with this construction method, as the number of mounted magnetoresistive effect elements increases, a large area is required on the surface where the external connection terminals 2 are formed, and there is a problem that the size of the head chip 1 is increased. In addition, the degree of freedom in designing the routing of the in-plane wiring pattern 5 is lowered, and there are problems such as an increase in product management burden due to an increase in wiring length and the manifestation of pattern density, and a reduction in yield.

  On the other hand, an in-plane wiring pattern for connecting the read lead of the magnetoresistive effect element and the external connection terminal is formed in the formation layer of the magnetoresistive effect element, and only the external connection terminal of each element is formed on the top layer of the chip. There is a construction method that exposes.

  According to this construction method, the in-plane wiring pattern can be formed differently for each layer, so that the increase in chip size accompanying the increase in the number of elements mounted can be eliminated, and the degree of freedom of wiring can be improved. is there.

  However, in this method, the in-plane wiring pattern must be formed within the upper layer gap thickness between the magnetoresistive effect element and the upper shield material. The thickness of the upper layer gap is as narrow as about 0.2 μm. Therefore, if wiring is formed within this narrow upper layer gap thickness, the wiring thickness must be made very small. For this reason, the wiring resistance of the in-plane wiring pattern increases, and there is a problem that it is difficult to detect the change in the resistance value of the magnetoresistive effect element according to the signal magnetic field of the magnetic recording medium, that is, the reproduction output with high accuracy. Further, power saving cannot be achieved in the recording / reproducing apparatus.

  The present invention has been made in view of the above-mentioned problems, and a multi-track magnetoresistive thin film magnetic head capable of detecting a reproduction output with high accuracy while avoiding an increase in wiring resistance while reducing the chip size and its manufacture It is an object to provide a method.

  In solving the above-described problems, the magnetoresistive thin film magnetic head according to the present invention is a shield made of a magnetic material with the formation width of the magnetoresistive element as a track width when viewed from the sliding surface side with the magnetic recording medium. A magnetoresistive effect type thin film magnetic head in which magnetoresistive effect elements are shifted in the track width direction and stacked in multiple layers through a material, and each read lead connected to each magnetoresistive effect element and each read lead In-plane wiring patterns that are connected to each other and formed in the same layer and interlayer wiring patterns that lead out each in-plane wiring pattern to the uppermost layer, and the in-plane wiring pattern is in a non-shielding region of the shield material It is formed thicker than the reproduction lead.

  The method of manufacturing a magnetoresistive thin film magnetic head according to the present invention includes a step of forming a lower shield material, a step of forming a magnetoresistive effect element on the lower shield material via a lower layer gap, and a magnetoresistive effect. A step of forming a read lead on the element, a step of forming an in-plane wiring pattern connected to the read lead, and a step of forming an upper shield material via an upper layer gap on the magnetoresistive element, In the step of forming the in-plane wiring pattern, the in-plane wiring pattern is formed in the non-formation region of the upper shield material and is formed thicker than the reproduction lead.

  In the present invention, since the in-plane wiring pattern is formed for each formation layer of each magnetoresistive effect element, when the lead of each element and the external connection terminal are collectively connected by wiring in the uppermost layer of the chip. In comparison, the chip size can be reduced.

  In the non-shielding region of the shield material, it is not necessary to consider electrical insulation with the shield material, so that the formation thickness of the in-plane wiring pattern can be increased. This makes it possible to reduce the wiring resistance by forming the in-plane wiring pattern thicker than the reproduction lead, and to detect the change in the resistance value of the magnetoresistive effect element according to the signal magnetic field of the magnetic recording medium with high accuracy. In addition, the power consumption of the recording / reproducing apparatus can be reduced.

  As described above, according to the magnetoresistive thin film magnetic head of the present invention, a change in the resistance value of the magnetoresistive element can be detected with high accuracy while reducing the head chip size, and the recording / reproducing apparatus The power consumption can be reduced.

  Further, according to the method of manufacturing a magnetoresistive thin film magnetic head of the present invention, a multitrack compatible magnetoresistive thin film magnetic head capable of preventing an increase in head chip size and deterioration in reproduction output can be manufactured. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a magnetoresistive thin film magnetic head (hereinafter referred to as “magnetic head”) 10 according to an embodiment of the present invention as viewed from the ABS surface (air bearing surface, sliding surface with a magnetic recording medium) side. The schematic structure of is shown. The magnetic head 10 is composed of an 8-channel magnetic head chip having eight magnetoresistive elements MR1 to MR8.

  The magnetic head 10 has a four-layer structure in which the formation width of the magnetoresistive elements MR1 to MR8 is a track width when viewed from the ABS surface, and the magnetoresistive elements MR1 to MR8 are shifted from each other in the track width direction via a shield material. It is configured by stacking.

  The magnetoresistive effect elements MR1 to MR8 of the layers L1 to L4 are formed so as to be embedded in the insulating materials INS1 to INS4 provided between the layers of the five layers of shield materials SLD1 to SLD5 made of a magnetic material. Two pieces are arranged between each layer of the shield material.

  That is, the first layer L1 includes the lower shield material SLD1, the first intermediate shield material SLD2, the insulating material INS1, and the magnetoresistive elements MR1 and MR2. The second layer L2 includes the first intermediate shield material SLD2 and the second intermediate shield material SLD2. An intermediate shield material SLD3, an insulating material INS2, and magnetoresistive elements MR3 and MR4 are included. The third layer L3 includes a second intermediate shield material SLD3, a third intermediate shield material SLD4, an insulating material INS3, and magnetoresistive elements MR5 and MR6. The fourth layer L4 includes the third intermediate shield material SLD4. The upper shield material SLD5, the insulating material INS4, and magnetoresistive elements MR7 and MR8 are included.

  The magnetoresistive effect elements MR1 to MR8 have the same configuration. The details of the formation region of the magnetoresistive effect element will be described with reference to FIGS. Here, FIG. 2 is an enlarged view schematically showing details of the portion A in FIG. 1, and FIG. 3 is a perspective view schematically showing the configuration of the magnetoresistive effect element.

In the magnetic head 10, a lower shield material SLD 1 made of a soft magnetic material such as Ni—Fe is formed on a nonmagnetic substrate 11 made of AL ₂ O ₃ —TiC (altic) or the like via an insulating layer 12. A nonmagnetic insulating film 21 made of a SiO ₂ film, an Al ₂ O ₃ film or the like is laminated on the lower shield material SLD1. On the nonmagnetic insulating film 21, magnetoresistive elements MR1 and MR2 (only MR2 is shown in FIG. 2) which are magnetosensitive parts are formed, and are further connected to these magnetoresistive elements MR1 and MR2, respectively. A hard bias film 13 is formed, and an electrode film 14 is laminated on the hard bias film 13.

  Here, the magnetoresistive elements MR1 to MR8 show the three-dimensional structure of FIG. 3, but in this embodiment, the magnetoresistive elements MR1 to MR8 are constituted by spin valves GMR (giant magnetoresistive elements). The spin valve GMR has a multilayer structure, and has a known configuration mainly including an antiferromagnetic layer, a pinned layer, a nonmagnetic layer, and a free layer.

  The pinned layer magnetization is fixed by the exchange coupling magnetic field from the adjacent antiferromagnetic film, and the free layer magnetization rotates in response to the magnetic field from the magnetic recording medium. The free layer magnetization is aligned in the track width direction by its own magnetocrystalline anisotropy and the magnetic field from the hard bias film 13, and is orthogonal to the pinned layer magnetization. Therefore, when a magnetic field from the magnetic recording medium enters, the free layer magnetization changes in a parallel (same direction) or antiparallel (reverse) direction to the pinned layer magnetization, and the fluctuation of the electric resistance value of the sense current generated at this time is changed. A reproduction signal can be obtained by reading.

  The magnetoresistive elements MR1 to MR8 have a planar shape formed in a substantially rectangular pattern, and one side edge of the magnetoresistive elements MR1 to MR8 faces the ABS surface (sliding surface). The formation width is the track width Tw.

  The hard bias film 13 is a permanent magnet film for removing the Barkhausen noise of the free layer, and is composed of, for example, a Co—Cr—Pt film. The electrode film 14 is a nonmagnetic conductive film for applying a sense current to the magnetoresistive elements MR1 and MR2, and is composed of, for example, a Cu, Au, Ti, Mo, Ta film or the like.

On the magnetoresistive effect elements MR1 and MR2 and the electrode film 14, a first intermediate shield material SLD2 made of Ni—Fe or the like is interposed via a nonmagnetic insulating film 22 made of SiO ₂ film, Al ₂ O ₃ film or the like. A film is formed.

  The first layer L1 is configured as described above. The second layer L2 is configured in the same manner as the first layer L1, and magnetoresistive elements MR3 and MR4 (only MR4 is shown in FIG. 2) on the first intermediate shield material SLD2 via the nonmagnetic insulating film 21. Further, a hard bias film 13 connected to each of the magnetoresistive effect elements MR3 and MR4 is formed, and an electrode film 14 is laminated on the hard bias film. A second intermediate shield material SLD3 made of Ni—Fe or the like is formed on the magnetoresistive effect elements MR3 and MR4 and the electrode film 14 with a nonmagnetic insulating film 22 interposed therebetween.

  The third and fourth layers L3 and L4 are configured similarly. The shield material in the uppermost layer is the upper shield material SLD5. Finally, the magnetic head 10 corresponding to 8 tracks on which the magnetoresistive effect elements of two layers are mounted is configured.

In the magnetic head 10 according to the present embodiment, the lower shield material SLD1, the magnetoresistive effect element MR1 (or MR2), and the first intermediate shield material SLD2 constitute one magnetic head portion, and the lower shield material SLD1 and the first shield material SLD1. The intermediate shield material SLD2 functions as a lower shield material and an upper shield material of the magnetic head portion. At this time, the nonmagnetic insulating film 21 functions as a lower layer gap, and the nonmagnetic insulating film 22 functions as an upper layer gap.
The first intermediate shield material SLD2, the magnetoresistive effect element MR3 (or MR4), and the second intermediate shield material SLD3 constitute one magnetic head portion, and the first intermediate shield material SLD2 and the second intermediate shield material SLD3. Respectively functions as a lower shield material and an upper shield material of the magnetic head portion.

Similarly, the second intermediate shield material SLD3, the magnetoresistive effect element MR5 (or MR6), and the third intermediate shield material SLD3 constitute one magnetic head portion, and the second intermediate shield material SLD3 and the third intermediate shield material. The SLD 4 functions as a lower shield material and an upper shield material for the magnetic head portion.
The third intermediate shield material SLD4, the magnetoresistive effect element MR7 (or MR8), and the upper shield material SLD5 constitute one magnetic head portion, and the third intermediate shield material SLD4 and the upper shield material SLD5 are the magnetic head. It functions as a lower shield material and an upper shield material respectively.

  In the magnetic head 10 configured as described above, when reproducing a magnetic signal recorded on a magnetic recording medium such as a magnetic tape, a sense current is applied to the magnetoresistive elements MR1 to MR8 via the electrode film 14. Is supplied. Moreover, the voltage value of these magnetoresistive effect elements is detected by a detection mechanism (not shown). The resistance value of the magnetoresistive effect element changes according to the signal magnetic field from the magnetic recording medium. Therefore, the voltage value of the sense current changes based on a change in the resistance value of the magnetoresistive effect element, and the signal magnetic field from the magnetic recording medium is detected by detecting the change in the voltage value.

  Since the magnetoresistive elements MR1 to MR8 are laminated in multiple layers while being shifted from each other in the track width Tw direction, the signal magnetic field recorded on the eight tracks of the magnetic recording medium can be detected simultaneously. As a result, it is possible to obtain a reproducing magnetoresistive thin film magnetic head 10 that supports multitrack of a high recording density tape-like magnetic recording medium such as a digital magnetic tape.

  Further, since the intermediate shield materials SLD2 to SLD4 are used as the upper shield material and the lower shield material of each magnetic head portion, the magnetic head 10 can be made thinner. According to the prototypes of the present inventors, it has been confirmed that the distance between the upper and lower layer elements can be formed to about 2.7 μm or less.

  In the magnetic head 10 having a thin structure as described above, the electrode films 14 are formed on the head chip corresponding to the magnetoresistive effect elements MR1 to MR8 formed by two in each of the layers L1 to L4. In forming a wiring pattern for connection to the upper external connection terminal 15, in the present invention, as schematically shown in FIGS. 4 and 5, the same layer is connected to the reproduction lead 24 connected to the electrode film 14. In-plane wiring patterns LP1 to LP8 that are routed inside, and interlayer wiring patterns LV1 to LV8 that lead out these in-plane wiring patterns LP1 to LP8 to the uppermost layer, respectively.

Here, FIG. 4 is a schematic sectional view of the magnetic head 10 in a direction perpendicular to the ABS surface 10a. FIG. 5 is a plan view of the magnetic head 10 as viewed from the top layer of the head chip. The arrangement example of the external connection terminals 15 and the in-plane wiring patterns LP1 to LP4 of each layer connected to the external connection terminals 15 are routed. An example is schematically shown.
The numbers attached to the end of the in-plane wiring pattern LP and the interlayer wiring pattern LV correspond to the numbers attached to the end of the magnetoresistive effect element MR.

  The in-plane wiring patterns LP1 to LP8 are formed in pairs corresponding to the layers L1 to L4, respectively, and are formed so as to connect between the reproduction lead 24 of the element in each layer and the interlayer wiring patterns LV1 to LV8. (FIG. 5). These in-plane wiring patterns LP1 to LP8 are electrically insulated from each other by the insulating materials INS1 to INS4 of the respective layers L1 to L4 (FIG. 4).

  Each of the in-plane wiring patterns LP1 to LP8 is made of, for example, a plating film such as Cu or Ni, and is formed to be thicker than the reproduction lead 24 in the non-formation region of the shield materials SLD2 to SLD5 immediately above it.

  The non-formation regions of the shield materials SLD2 to SLD5 correspond to the rear side (the side opposite to the ABS surface 10a) of the magnetic head 10 and the side thereof. Thus, the reproduction leads 24 and the interlayer wiring patterns LV1 to LV4 can be connected with low resistance while avoiding contact with the shield materials SLD2 to SLD5.

  In the present embodiment, the formation thickness of the in-plane wiring patterns LP1 to LP8 is set such that the upper layer gap (nonmagnetic insulating film) provided between the magnetoresistive elements MR1 to MR8 and the shield materials SLD2 to SLD5 located thereabove. It is formed thicker than the formation thickness of 22. With this configuration, the in-plane wiring patterns LP1 to LP8 overlap the shield materials SLD2 to SLD5 in the thickness direction. In the present embodiment, the amount of overlap δ is about 1.35 μm, but this amount of overlap δ can be arbitrarily adjusted, and can be set differently between the layers.

  In particular, in the present embodiment, the formation thickness of the in-plane wiring patterns LP1 to LP8 in each layer L1 to L4 is set to be equal to or less than the formation thickness of the shield materials SLD2 to SLD5 in the layer. This ensures electrical insulation between the upper and lower layers.

  On the other hand, the interlayer wiring patterns LV1 to LV8 are configured as interlayer connection wirings that electrically connect the in-plane wiring patterns LP1 to LP8 of each layer to the external connection terminal 15 on the uppermost layer of the magnetic head 10, respectively. A pair is formed for each L4 (FIG. 5). These interlayer wiring patterns LV1 to LV8 are formed by alternately laminating conductive materials constituting the shielding materials SLD2 to SLD5 and conductive materials constituting the in-plane wiring patterns LP1 to LP4 (FIG. 4).

  A plurality of external connection terminals 15 are formed corresponding to the respective interlayer wiring patterns LV1 to LV8 (a total of 16 in the present embodiment) (FIG. 5). Although not shown, lead wirings are joined to each of the external connection terminals 15, and the external connection terminals 15 are connected to detection mechanisms (not shown) that detect changes in the resistance values of the magnetoresistive elements MR 1 to MR 8 via these lead wires. Is connected.

  According to the magnetic head 10 of the present embodiment configured as described above, the in-plane wiring patterns LP1 to LP8 are formed for the respective formation layers of the magnetoresistive effect elements MR1 to MR8. Compared to the conventional configuration (FIG. 20) in which the reproduction leads of each element and the external connection terminals are collectively connected in the uppermost layer, the wiring area can be saved and the chip size can be reduced. it can.

  In addition, since the in-plane wiring patterns LP1 to LP8 are routed and formed in the regions where the shield materials SLD2 to SLD5 are not formed, it is not necessary to consider electrical insulation from the shield materials SLD2 to SLD5, and the in-plane wiring patterns LP1. The formation thickness of LP8 can be increased. As a result, the in-plane wiring patterns LP1 to LP8 are formed thicker than the reproducing lead 24 to reduce the wiring resistance, and the resistance value changes (reproducing output) of the magnetoresistive effect elements MR1 to MR8 according to the signal magnetic field of the magnetic recording medium. ) Can be detected with high sensitivity, and the power consumption of the recording / reproducing apparatus can be reduced. In addition, changes in specifications on the recording / reproducing apparatus side such as a rotating drum and system can be minimized.

  Furthermore, as shown in FIG. 5, if the wiring overlap of the in-plane wiring patterns LP1 to LP8 is reduced as much as possible between the layers, the wiring capacity between the wiring patterns can be reduced, and the reproduction output with higher sensitivity can be achieved. The detection action can be ensured.

Next, a method for manufacturing the magnetic head 10 configured as described above will be described with reference to FIGS. In the following description, specific materials and numerical values are given, but of course not limited thereto.
6 to 17 are process cross-sectional views for explaining a method of manufacturing the magnetic head 10, and FIGS. 18 and 19 are plan views showing examples of routing of the in-plane wiring patterns LP1 to LP8 in the layers L1 to L4.

First, as shown in FIG. 6, an Al ₂ O ₃ or SiO ₂ film or the like is formed on a nonmagnetic substrate 11 made of, for example, an AL ₂ O ₃ —TiC material for the purpose of improving the insulation and surface properties of the substrate 11. An insulating layer 12 is formed.

Next, a lower shield material SLD1 is formed on the insulating layer 12. The lower shield material SLD1 is formed of a plating film having a thickness of about 2.5 μm made of a soft magnetic material such as permalloy. The lower shield material SLD1 is formed by processing this plating film into a predetermined shape. Then, a nonmagnetic insulating film 21 made of Al ₂ O ₃ or SiO ₂ film having a thickness of about 0.06 μm is formed on the lower shield material 12 as a lower layer gap.

Subsequently, as shown in FIG. 7, a lower insulating thickening film 31 having a thickness of about 0.1 μm made of Al ₂ O ₃ , SiO ₂ film or the like is formed on the nonmagnetic insulating film 21. This lower insulation thickening film 31 is provided to reinforce the insulation between the in-plane wiring pattern LP1 (LP2) to be formed later and the lower shield material SLD1, and in the formation region of the magnetoresistive effect element An opening 31a is formed.

Next, as shown in FIG. 8, a multilayered GMR film 41 constituting the magnetoresistive element MR1 (MR2) is formed on the nonmagnetic insulating film 21 opened by the opening 31a by, for example, sputtering. . The thickness of the GMR film 41 is about 0.05 μm. Then, the GMR film 41 is etched into a predetermined shape, and the hard bias film 13 and the electrode film 14 are sequentially formed (FIG. 3). Thereafter, as shown in FIG. 9, a nonmagnetic insulating film 22 made of Al ₂ O ₃ or SiO ₂ film having a thickness of about 0.07 μm is formed on the GMR film 41 and the lower insulating thick film 31 as an upper layer gap. Form a film.

  Subsequently, after the nonmagnetic insulating film 22 is etched into a predetermined shape, a reproducing lead 24 made of Cu, Au, or the like and having a thickness of about 0.2 μm is formed by sputtering, for example, as shown in FIG. The reproduction lead 24 overlaps a part of the underlying electrode film 14, whereby the electrode film 14 and the reproduction lead 24 are electrically connected.

  Next, as shown in FIG. 11, the in-plane wiring pattern LP1 (LP2) is formed so as to overlap a part of the reproduction lead 24. The in-plane wiring pattern LP1 (LP2) is composed of a metal plating film made of Cu or the like and having a thickness of about 1.5 μm. The in-plane wiring pattern LP1 (LP2) is formed thicker than the regenerative lead 24. However, since it is formed by a plating method, it does not require much time for film formation.

  As a method of forming the in-plane wiring pattern LP1 (LP2), after forming a resist pattern that is slightly larger than the wiring pattern, Cu as a base film for wiring plating is formed by sputtering or the like. Thereafter, a photoresist is further applied, and a desired wiring pattern is formed in the previously formed resist pattern. Then, after the in-plane wiring pattern LP1 (LP2) is formed by plating, the resist pattern is removed, and the Cu base film is removed by ion milling or the like. Thereafter, by removing the previously formed resist pattern, the in-plane wiring pattern LP1 (LP2) shown in FIG. 11 is formed.

  FIG. 18A shows an example of wiring routing of the in-plane wiring pattern LP1 (LP2). These wiring patterns LP1 (LP2) are formed in the non-formation region of the first intermediate shield material SLD2 formed in the next process (FIG. 13).

  Subsequently, as shown in FIG. 12, an upper insulating thick film 32 having a thickness of about 0.15 μm is formed on the reproduction lead 24 and the in-plane wiring pattern LP1 (LP2) by, for example, a lift-off method. Here, an opening 32a for forming the interlayer wiring pattern LV1 (LV2) is formed at a predetermined position on the in-plane wiring pattern LP1 (LP2).

  Next, as shown in FIG. 13, a plating film 51 constituting the first intermediate shield material SLD2 is formed. At this time, simultaneously with the formation of the permalloy film 51, the permalloy plating film 51 constituting the interlayer wiring pattern LV1 (LV2) is formed on the in-plane wiring pattern LP1 (LP2) through the opening 32a of the upper insulating thickening film 32. Form.

  The permalloy film 51 is formed by depositing permalloy or the like as a base film by sputtering or the like, and then applying a resist thereon to form a frame pattern having a predetermined shape. Then, after the permalloy film 51 is formed by plating, the frame pattern is removed, and the base film is removed by etching. Further, a cover resist for removing the unnecessary permalloy film is formed, and after removing the unnecessary permalloy film by etching, the cover resist is dissolved and removed.

Finally, as shown in FIG. 14, after the entire upper surface of the head is filled with an insulator 35 such as Al ₂ O ₃ , the upper surface of the head is polished and planarized by a predetermined amount, and the permalloy film 51 is exposed on the upper surface of the head. . Thereby, the first intermediate shield material SLD2 having a thickness of about 2.5 μm to 2.75 μm is formed.

  As described above, the first layer L1 having the lower shield material SLD1, the first intermediate shield material SLD2, and the magnetoresistive element MR1 (MR2) is manufactured. Next, a step of manufacturing the second layer L2 on the first layer L1 is performed (FIGS. 15 to 17).

  The second layer L2 and subsequent layers are also manufactured in the same manner as the above-described steps. At this time, the magnetoresistive effect element MR3 (MR4) is formed to be shifted from the magnetoresistive effect element MR1 (MR2) of the first layer L1 by a predetermined amount (one track in this example) in the track width direction (in this example). 1 and 2).

  In addition, openings 36 are formed in the insulating films 21, 22, and 31 constituting the gap layer in the second layer L2 corresponding to the position where the interlayer wiring pattern LV1 (LV2) is formed in the first layer L1. (FIG. 15). Then, in the second layer L2, the in-plane wiring pattern LP3 (LP4) is formed by plating with respect to the reproduction lead 24 connected to the magnetoresistive element MR3 (MR4). FIG. 18B shows an example of forming the in-plane wiring pattern LP3 (LP4) in the second layer L2.

  Therefore, in the present embodiment, simultaneously with the step of forming the in-plane wiring pattern LP3 (LP4), the Cu plating film 50 constituting the in-plane wiring pattern LP3 (LP4) is formed in the opening 36 to form a base layer. It is laminated on the permalloy film 51 (FIG. 16). Simultaneously with the step of forming the second intermediate shield material SLD2 by the plating method, as shown in FIG. 17, in the opening 37 formed in the insulating material INS2 covering the uppermost plating film 50 of the interlayer wiring pattern LV1 (LV2). Then, the permalloy plating film 51 constituting the second intermediate shield material SLD2 is formed.

  Thereafter, in the formation process of the third and fourth layers L3 and L4, the interlayer wiring patterns LV1 (LV2) are alternately stacked with the constituent materials of the in-plane wiring pattern LP and the shield material SLD, and the terminal surfaces thereof are always heads. It is exposed on the top surface of the chip. Finally, as shown in FIG. 4, the external connection terminals 15 are processed in the uppermost layer of the head chip.

  The other interlayer wiring patterns LV2 to LV3 are formed in the same manner in any part. Examples of routing of the in-plane wiring patterns LP5 (LP6) and LP7 (LP8) in the third layer L3 and the fourth layer L4 are shown in FIGS. 19A and 19B, respectively.

  As described above, according to the method of manufacturing the magnetic head 10 of the present embodiment, the in-plane wiring patterns LP1 to LP8 are formed for each formation layer of the magnetoresistive elements MR1 to MR8. Compared with the conventional method (Fig. 20) in which the reproduction leads of each element and the external connection terminals are collectively connected in the uppermost layer (Fig. 20), the wiring area can be saved, and the degree of freedom in wiring design can be improved. The chip size of the head 10 can be reduced.

  Further, since the in-plane wiring patterns LP1 to LP8 are routed in the non-formation regions of the shield materials SLD2 to SLD5, the wiring thickness of the in-plane wiring patterns LP1 to LP8 can be increased, thereby reducing the wiring resistance. Thus, the resistance value change of the magnetoresistive effect elements MR1 to MR8, that is, the reproduction output can be detected with high sensitivity.

  The embodiment of the present invention has been described above. Of course, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

  For example, in the above embodiment, the magnetic head 10 has a four-layer structure corresponding to eight tracks on which eight magnetoresistive elements are mounted, but the number of elements mounted and the number of layers are not limited to this. Further, the number of elements mounted per layer is not limited to 2, and can be changed as appropriate according to the system specifications.

  In the above embodiment, the giant magnetoresistive effect element (GMR) is applied as the magnetoresistive effect element, but an anisotropic magnetoresistive effect element (AMR) may be applied instead.

  Further, in the above embodiment, the magnetic head in which the magnetoresistive effect element is exposed on the ABS surface has been described as an example. However, a flux guide element is formed on the ABS surface, and the rear side of the flux guide element is interposed therebetween. The present invention can also be applied to a magnetic head in which a signal magnetic field is introduced to the side magnetoresistive effect element.

  Furthermore, the method of manufacturing a magnetic head according to the present invention can also be applied to the manufacture of a magnetoresistive thin film magnetic head having a single-layer structure, whereby the head chip can be made thinner.

1 is a schematic front view of a magnetoresistive thin film magnetic head 10 according to an embodiment of the present invention as viewed from the ABS side. It is an enlarged view which shows the detail of the A section in FIG. It is a perspective view which shows typically the structural example of magnetoresistive effect element MR1-MR8. 3 is a side cross-sectional view illustrating an example of wiring routing inside a magnetic head 10. FIG. 2 is a plan view showing an example of wiring routing of in-plane wiring patterns PL1 to PL2 of each layer of the magnetic head 10 and an example of arrangement of external connection terminals 15. FIG. FIG. 7 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process of forming the lower shield material SLD1 and the lower layer gap 21. FIG. 7 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming a lower insulating thick film 31. FIG. 7 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming the GMR film 41. FIG. 4 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming an upper layer gap 22. . FIG. 6 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming a read lead 24. FIG. 6 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming an in-plane wiring pattern LP1 (LP2). FIG. 6 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming an upper insulating thick film 32. It is process sectional drawing explaining the manufacturing method of the magnetic head 10, and has shown the formation process of the metal plating which is a constituent material of a shielding material and an interlayer wiring pattern. FIG. 4 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and shows a polishing process of the head upper surface. FIG. 7 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process for forming the GMR film 41 and the gap layer in the second layer L2. FIG. 7 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a process of forming an in-plane wiring pattern LP3 (LP4) and an interlayer wiring pattern LV1 (LV2) in the second layer L2. FIG. 4 is a process cross-sectional view illustrating a method for manufacturing the magnetic head 10 and illustrates a final formation process of the second layer L2. FIG. 2 is a top view of a head chip showing an example of routing of an in-plane wiring pattern, in which A indicates a first layer L1 and B indicates a second layer L2. FIG. 3 is a top view of a head chip showing an example of routing of an in-plane wiring pattern, in which A indicates a third layer L3 and B indicates a fourth layer L4. FIG. 6 is a top view of a head chip of a conventional multi-track magnetoresistive thin film magnetic head.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Magnetoresistance effect type thin film magnetic head, 14 ... Electrode film, 15 ... External connection terminal, 21 ... Lower layer gap, 22 ... Upper layer gap, 24 ... Reproduction lead, 31 ... Lower layer insulation thickening film, 32 ... Upper layer insulation thickening Films 41... GMR film 50. Cu plating film 51. Permalloy plating film INS1 to INS4 Insulating material L1 to L4 Layer LP1 to LP8 In-plane wiring pattern LV1 to LV8 Interlayer wiring pattern MR1 ~ MR8 ... magnetoresistive effect element, SLD1 to SLD5 ... shield material, Tw ... track width.

Claims (1)

As viewed from the sliding surface side with the magnetic recording medium, the formation width of the magnetoresistive effect element is a track width, and the magnetoresistive effect element is placed on the track via a shield material made of a conductive material having magnetism and an insulating film. A method of manufacturing a magnetoresistive thin film magnetic head laminated in multiple layers shifted from each other in the width direction ,
Forming a first insulating film;
Forming a first magnetoresistive element on the first insulating film;
Forming a first read lead on the first magnetoresistive element;
Forming a first in-plane wiring pattern connected to the first reproduction lead thicker than the first reproduction lead;
A second insulation having a first hole located on the first in-plane wiring pattern on the first magnetoresistive element, the first reproduction lead, and the first in-plane wiring pattern. Forming a film;
Forming a first shield material in a region where the first in-plane wiring pattern is not formed, filling the first hole, and being electrically connected to the first in-plane wiring pattern; Forming a first filler made of a conductive material constituting one shield material;
Forming a third insulating film having a second hole located on the first filler on the first shield material and the second insulating film;
Forming a second magnetoresistive element on the third insulating film, shifted from the first magnetoresistive element in the track width direction;
Forming a second read lead on the second magnetoresistive element;
A second in-plane wiring pattern connected to the second reproduction lead is formed thicker than the second reproduction lead, fills the second hole, and electrically connects to the first filler. Forming a second filler made of a conductive material constituting the second in-plane wiring pattern connected to
A third hole located on the second in-plane wiring pattern, on the second magnetoresistive effect element, the second reproduction lead, and the second in-plane wiring pattern, and the second Forming a fourth insulating film having a fourth hole located on the filler;
A second shield material is formed in a region where the second in-plane wiring pattern is not formed, and the third and fourth holes are filled, and the second in-plane wiring pattern and the second filling material are filled. Forming a third filler made of a conductive material constituting the second shield material, which is electrically connected to each other .

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